<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<style>
  .active {
    color: red;
  }
  .line {
    color: blue;
  }
</style>
<body>
<div id="app">
  <h2 class="title" v-bind:class="[active, line]">{{message}}</h2>
</div>
<script src="../js/vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
          message: "你好",
          active: 'active',
          line: 'line'
        }
    })
</script>
</body>
</html>
